Stomach AcidityCARNIVORE: Less than or equal to pH 1 with food in
stomach
OMNIVORE: Less than or equal to pH 1 with food in stomach
HERBIVORE: pH 4 to 5 with food in stomach
HUMAN: pH 4 to 5 with food in stomach

Stomach Capacity
CARNIVORE: 60% to 70% of total volume of digestive tract
OMNIVORE: 60% to 70% of total volume of digestive tract
HERBIVORE: Less than 30% of total volume of digestive tract
HUMAN: 21% to 27% of total volume of digestive tract

Length of Small Intestine CARNIVORE: 3 to 6 times body length
OMNIVORE: 4 to 6 times body length
HERBIVORE: 10 to more than 12 times body length
HUMAN: 10 to 11 times body length

ColonCARNIVORE: Simple, short and smooth
OMNIVORE: Simple, short and smooth
HERBIVORE: Long, complex; may be sacculated
HUMAN: Long, sacculated

LiverCARNIVORE: Can detoxify vitamin A
OMNIVORE: Can detoxify vitamin A
HERBIVORE: Cannot detoxify vitamin A
HUMAN: Cannot detoxify vitamin A

According to biologists and anthropologists who study our anatomy and
our evolutionary history, humans are herbivores who are not well suited
to eating meat.

Unlike natural carnivores, we are physically and psychologically
unable to rip animals limb from limb and eat and digest their raw flesh.
Even cooked meat is likely to cause human beings, but not natural
carnivores, to suffer from food poisoning, heart disease, and other
ailments.

People who pride themselves on being part of the human hunter
tradition should take a second look at the story of human evolution.
Prehistoric evidence indicates that humans developed hunting skills
relatively recently and that most of our short, meat-eating past was
spent scavenging and eating almost anything in order to survive; even
then, meat was a tiny part of our caloric intake.

Humans lack both the physical characteristics of carnivores and the
instinct that drives them to kill animals and devour their raw
carcasses. Ask yourself: When you see dead animals on the side of the
road, are you tempted to stop for a snack? Does the sight of a dead bird
make you salivate? Do you daydream about killing cows with your bare
hands and eating them raw? If you answered "no" to all of these
questions, congratulations—you're a normal human herbivore—like it or
not. Humans were simply not designed to eat meat.